The present invention relates to the improvement of a laryngoscope. A laryngoscope is a device that is used to position an endotrachel tube in a patient's trachea. The primary purpose of a laryngoscope is to expose the aditus of larynx thereby allowing an endotracheal tube to be inserted past the vocal cords into the patient's trachea. The insertion of an endotracheal tube provides an airway for ventilation and prevents foreign substances from entering the patent's trachea and lungs.
Laryngoscopes generally have three main parts, a handle, a blade and a light source. A good example of this can be found in U.S. Pat. No. 2,433,705 (Palmeter). The operator grasps the handle and inserts the blade through the patient's oral cavity into the patient's laryngopharynx. The blade displaces the tongue and throat tissue exposing the aditus of larynx. Laryngoscope blades come in different sizes and curvatures and are commonly detachable from the handle. An example of a laryngoscope having a substantially straight blade is the "Jackson" laryngoscope blade. The "Miller Blade," commonly used in the art, is an example of a blade that is substantially straight with a curved tip. A blade that is curved through out its length can be seen in U.S. Pat. No. 2,354,471 (MacIntosh).
Generally, traditional laryngoscopes with straight or curved blades do the job effectively. There are, however, patients in which traditional laryngoscopes do not work effectively. This may be due to the patient having congenital deformities such as, a short "bull" neck, protruding or carious upper incisor teeth, over development of the tongue, a short ridged epiglottis, a narrow oral cavity or pathological conditions such as cervical arthrosis or mandibular anchylosis. When an emergency situation occurs, these patients are at great risk because the operator may have just seconds to expose the vocal cords to establish an airway or risk losing the patient.
Inventors have tried to address this situation but have been unable to come up with a device that is effective and that has received wide acceptance from the medical community. Blades that are capable of changing curvature like that found in U.S. Pat. No. 4,573,451 (Bauman) and U.S. Pat. No. 5,584,795 (Valenti) have been tried. So has a blade that moves on a pivot connection, U.S. Pat. No. 4,573,451 (Kadell). These blades, however, are difficult to use in emergency situations and are not effective on all patients. Corrazzi Jr., in U.S. Pat. No. 4,360,008 invented a laryngoscope that has a blade with a movable distal tip. The movable tip is used to anteriorly displace the soft tissue of the laryngeal area, such as the epiglottis, but may only result in posterior displacement of the entire blade. Although, the posterior displacement could be compensated by rotation of the blade at the proximal base, the rotation may, however, be prohibited or restricted by the patient's teeth.
Another problem with Corrazzi's invention is the placement of the actuating lever that moves the distal tip. This problem is also seen in Kadell's invention. In both inventions the activation lever is projected alongside the handle. When inserting a laryngoscope the operator must tightly grasp the handle. The placement of the activating lever as disclosed in the Corrazzi patent and Kadell patent would impede the operators ability to grasp of the handle and may result in the inadvertent engagement of the respective inventions during insertion. This could impede proper positioning of the laryngoscope blade and may result in injury to the patient.
In addition, the Corrazzi invention as disclosed has another potential problem. If the biasing spring fails the single tip may remain in the activated state. This could interfere with the removal of the blade, inhibit repositioning of the blade and may even result in injury to the patient.
The need for a laryngoscope that will expose the aditus of larynx in those patients in which traditional laryngoscopes do not work in a simple manner has been long felt. My present invention satisfies those needs.